1. Field of the Invention
The present invention relates to controlling a legged robot so that the robot does not fall. More particularly, the present invention relates to controlling the robot using a two-phase strategy for responding to a force disturbance.
2. Description of Background Art
Future humanoid robots are expected to freely reside within everyday human environments and to physically interact with their surroundings. A key factor for robots' successful co-existence with humans will lie in their ability to physically interact with people. This means that a robot should be able to withstand unexpected force disturbances.
In particular, a robot should be able to maintain its balance even when it has been subjected to an unexpected force. The term “balance” generally refers to the preservation of overall rotational stability or equilibrium. If a robot's overall rotational equilibrium is lost, the robot can fall. A falling robot can injure nearby people and/or badly damage the robot itself.
What is needed is a control strategy that enables a robot to maintain its balance when subjected to an unexpected force.